Do I need to rebuild my motor ?

I traced an oil leak from the floor,via the inside of the rear sill/rocker panel,via the outside of the fuel tank,via the fibreglass air inlet housing,via the inside of my carb filter box.
My understanding is that this is caused by excessive crankcase pressure,which is caused by worn rings/bores or leaking valve stem seals.The car is a low mileage 81 carb gtb and runs reasonably well, but I have never checked the exhaust for blue smoke as I thought it would be just about run in let alone worn out.I would appreciate any advice as an engine rebuild is very worrying for me.

 

Perform a compression check and a leak down test and based on the results go from there. Inexpensive to do or have done but will tell you if you need to invest $20K to rebuild the engine. Good luck and let us know how you make out.

 

I have just done a compression test on cylinders 1-4 ( much easier) and they ranged from 162-170 psi,took the air filter lid off and could not detect any thing coming out of the small button type exit for the breather pipe, even with some engine revs.I know its not very thorough but I did expect to see something with this. This is one of the plugs,same as others I pulled out.
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How long has it been since the vapor separator has been serviced?

And explain the part about it being an 81 carbureted car. Your profile has zero information that might help us help you but yet?

 

Not following you here as these two things don't agree. A blocked oil liquid-vapor separator could cause engine oil to leak out elsewhere as Rifledriver indicated, but not inside carb filter box -- are you sure you know where the oil is leaking from?

 

Now, don't anyone get snarky! I will be asking a series of shadetree questions
First, how much and how fast is it leaking? Regardless of where it emanates...

 

Isn't it time for some pics of the inside of the a/f housing?

 

Hi Bert (?),
That plug looks fine, and the compression numbers are good. If you're wondering about the condition of your rings, then the leakdown test will provide more important data.

As Rifledriver and Steve M indicated, we need more information to help you out - those guys are pros, and will steer you straight!

 

I dont know how long since vapor separator has been serviced, I dont even know what it is but will look into it now. My car is a uk RHD 1981 carb gbt with about 16,000 miles.I am not sure where the oil is coming from,I have only traced it back to inside the air filter box.Before cleaning, it had a film of oil everywhere,within the filter,so carbs,filter base and lid,and it would collect more in the rubber connector creases which is attached to the air box inlet.As to the amount of leakage,thats a bit difficult to say because I only noticed the drips when it was parked up and that would be just the excess remnants from the drive.

 

This seems like mine,cant see the vapour separator though.
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Uhhh, you haven't divulged how fast and the amount of oil that is coming out...you're jumping the gun asking about a major repair when we don't even know the severity of your leak. You obviously don't know what that plug is telling you either, so I'll just leave you to hash it out on your own...It's obvious that even if Rifle and Steve diagnose your problem, you won't be able to fix it on your own, so why waste everyone's time and just take it to a Ferrari dealership for repair...good luck

 

Wow, you went snarky 1st before anyone else had a chance.

 

Yes, your dry sump system has a little bit different layout -- the liquid/vapor separator is built into the top of the oil tank so it isn't noticeable, but I've never come across any real detailed figure of it, nor technical information, other than the brief mention of it in your OM. It does have a note to service it occasionally, but this dry sump layout does add another possibility for getting unwanted oil into the carb air filter housing (if that's what's happening) - adding too much oil by using the wrong oil level measuring process. If someone checks the oil level when cold without having run the engine for an extended period of time, the bulk of the oil will be down in the sump so a lot of extra oil would have to be added to bring the level in the tank up to "full". So would just recommend you first make sure the oil level is correct per the specified measuring process (warm engine idling, shut off, measure oil level immediately) before anything else -- just a suggestion...

Understood, but it's more technically accurate to say that you have "a late UK RHD 308 GTB that was first registered (or had paperwork generated) in 1981" as "model year" doesn't really exist on any carbed 308 -- although many pieces of paperwork, even here in the US, will have a "model year" shown on it ("Model year" is something encoded in the 17-digit US VIN, and F didn't have to start complying with the 17-digit VIN until the injected V8 models were introduced.)

A euro b is damn good looking - enjoy!

 

Dave, sometimes you just have to...Especially when someone doesn't know how to check their oil...I'm a bad boy...hehehehe

 

I think there are about a dozen carb'ed cars with the 17 digit VIN - I've got one of them 😀
Apologies for the pendantry, back to oil leaks...




Sent from my ONEPLUS A3003 using Tapatalk

 

You're absolutely right, of course. It is a fact that the UK cars were the first to be stamped with a full 17 digit VIN: the very, very last batch of UK 308GT4 are the only example of cars with the specific VIN letters for the very, very rare "Dino" manufacturer's VIN (ZDF...instead of ZFF...)

Rgds

 

S.M ,Your reply makes logical sense. I have always checked my oil 15 minutes after a good hard drive and its always been within limits,but will check again next time. I think I will put a temporary catch can on the breather pipe to see what happens as I cant see another entry point for the oil to the air filter box
lastly to be correct,I should say that my car is registered in 1981, but has a 17 digit VIN,whatever that implies Im not sure.

 

...only that your car is among the very last batch of carbed 308 GTB produced, like Andy's.
The last dozen or so RHD 308 GTBs are the only carbed cars to have received a full 17-position VIN. Is it indiscreet to ask what her chassis number is?

Rgds

 

Interesting -- is it decodable in a meaningful way with "model year" included (there's a decoder available at www.red-headed.com), or is it partially decodable (for example, nerofer indicating manufacturer identification is there and maybe something like the intended market), or is it just manufacturer plus a bunch of zeros (and maybe the SN) to build it up to 17 digits?

 

I'm no expert on these things (or anything really) but Nerofer is

There was a thread about the last carb'd car:
http://www.ferrarichat.com/forum/308-328-sponsored-yellow-compass-group/431150-last-carbd-308-a.html

And within that thread is a picture of my VIN plate
http://www.ferrarichat.com/forum/142789167-post44.html

 

Yes, that's just manufacturer, engine type, safety system, chassis type, and market -- the block of four zeros is where a US-legal VIN would show something for "US model year".

 

That spark plug shows no sign of oil getting into that combustion chamber. If the others in that bank look like that, I'd say that no oil is getting into THAT BANK.

As others have said, it's a MIGHTY big leap from having some oil dripping to concluding the engine needs rebuilding! My opinion - admittedly based on very little information - is that the engine itself is perfectly OK other than a leak from a gasket/seal/oil system connection somewhere.

You could try what some folks do - put some 20W50 non-synthetic oil in it and hope that the thicker oil will reduce the leakage!

But better would be to do as you are doing and locate/fix the leak.

 

Yep Steve; remember that, even in 1989, my two 328s, ZFFWA19B000081085 and ZFFWA20B000080515 have their VIN spelled about the same, without any digit for model year, (the "W" in fourth position indicates an euro, non-cat engine; "X" is the catalysed 3,2 in American variant, "C" the catalysed swiss variant)

What we know is that probably Ferrari just adopted the international 17-position VIN at the specific time bracket for production of the very last batch of carbed cars, and for some reason or the other, only the last dozen or so UK RHD cars received one.
And the last batch of UK RHD Dinos 308 GT4s, which make these ones all the more interesting, because the only very select batch of cars (maybe a dozen?) to have a stamped 17 position VIN beginning by "ZDF..." (unless Ferrari resurrects the "Dino" brand one day, that is...).

For the time being, we do not know of any other carbed 308 with a stamped 17 position VIN than UK cars.

Rgds

 

Just a side question -- do you have a reference for waiting the 15 minutes on your dry sump? I know on the later wet sump injected models they added the time delay (and my guess would be that they did this to let things settle down inside the wet sump due getting some erroneous readings if done too quickly due to frothing or dripping). Also know that it shouldn't make much difference either way, but just curious as your OM does not indicate any time delay after engine shutoff is needed.

 

Yes, I had the same question. If my memory is right, the Owner's Manual say that oïl level on a 308 with dry sump engine should be done just after stopping the engine, but still hot. Some friends check it with the engine at idle?

Rgds